Balanced compressor



M. F. HILL ETAL BALANCED COMPRESSOR Oct. 16, 1945.

Filed Sept. 1, 1958 7 Sheets-Sheet 1 INVENTORS Oct. 16, 1945. M. F. HMEm 2 38 896 BALANCED COMPRESSOR Filed Sept. 1, 1938 7 Shets-Sheet 2INVENTORS w c1 .uau

Oct. 16,1945. M. F. HILL ETAL BALANCED COMPRESSOR Filed Sept. 1, 1938 7SheetsSheet 3 INVENTORS M mmu Oct 16; 1945.

M. F. HILL EIAL BALANCED COMPRESSOR Filed Sept. 1, 1958 7 Sheets-Sheet 4212 an an al A lol INVENTORS Oct. 16, 1945. m. HILL Em 2 386,896

BALANCED COMPRESSOR Filed Sept. 1. 1938 7 Sheets-Sheet 5 I75 I iINVENTORS M. F. HILL ETAL BALANCED COMPRESSQR @izfi. 16, 1945 FiledSept. 1-. 1938 7 Sheets-Sheet 6.

' IN VEN TORS M.F. HILL ET AL BALANCED COMPRESSOR,

Filed Sept. 1, 1938 7 Shets-Sheet 7 Patented on. 16, 1945" UNITED STATESPATENT OFFJCE BALANCED COMPRESSOR Francis A m, 2nd,

Westport, Conn.

toothed sears. one within and eccentric to the other, operating as adisplacement mechanism for pressure fluids, particmarly for the compression and expansion of gases, and hold balance systems tending to floatthe rotating members from their bearings so that they may operate underpressures greater than the hearing surfaces themselves can carry. Manyof its features are useful in connection with liquids.

In the patent to Myron F. No. 1,682,564 a displacement rotor or nearmechanism was shown for such purpose in which the outer rotor was drivenby a motor shaft acting as a drive device in order to maintain the toothcontacts tight, regardless of backlash whether intentional or due towear. These tooth contacts separated chambers between the teeth whiletheywere closing in a compressor (or opening in an engine) and theeflicienoy of the mechanism largely depended on keeping the contactstight, since openings between the teeth permit pressure gases in achamber to escape to lower pressure chambers without accomplishingintended results.

One way of maintaining such contacts tight is to connect the drivedevice to the outer rotor, and the patent above mentioned employed .adriving plate or hell which was mounted on a motor shaft and carried anouter rotor near its outer perimeter. These parts rotated in :a casing.When used for compressing air to higher pressures, to 100 lbs. .i'orexample, the pressure Q seeped out through the running joints into thecasing and to the hack of the plate, reroing the rotors against thetrout cover plate, causing friction, heat, and loss of power; and. withthe lubricant adopted tor substantialiy isothermal air compression,causing it to m and retard operation. Various eflorts were made toovercome these obstacles, such as pressure balancing areas, thrusthearings, etc, in that mechanism they proved too and uncertain to berelied upon. Journal hearings were also inadequate for the heavy "workthe rotors were capable oi mentor-name, due to the necessity of tightbearing his for centering the rotors, and the inevitable. heating and"freezins that ensued. 1

Our invention aims to solve these problems and provide means to enablethe rotors to success-' ly periorm the high pressure work of a pistonand cylinder displacement mechanism now generally used for thesepurposes.

In the patent to Myron F. Hill, 1,682,565, the rotors were mountedbetween two side walls 1, 1933, Serial No. 227.954

which are secured to each other, so that they received equal gaspressures atrom the roior chambers between containing gas pressuresvarying from in chamber.

members with relaifion to the rotor that it drives,

to prevent the motor from lacing tipped by the drive device out of itsplane of action. "Ihe construction in the shove mentioned patent did notaccomplish this result since the hearings on one side of the shaft wouldloose so ems would not normal to the plane of action provided for therotors. caused the rotor to cant, which resulted in point contactsbetween the teeth of the two rotors instead of I necessary line contactsacross teeth .lrom one side wall to the other, allowing escape ofpressure gases between at either side of the point of contact. sheet ofsuch crevices in liquid pumps i of minor import, in compressors,particularly at high pressure they ds-v stray emclency.

One way not the only so! getting and proper tooth action is to drive theouter rotor Toy a cylinder acting as a pulley or as an armature shafit,or Toy some suit-- able device mounted hearings on [each of the centerline oi the rotors, preierably oi the tooth chamber sidewalls. Both thedrive rotor and the driven rotor then rotate in the same plane. Anothermethod of securing result appears later.

order to float rotors (ofi their hearings, liquid pressure from thehigher onessure port or passageway, the con-- ducted to recesses orchannels which may be located between a plurality of landings or limeswhich constitute the proper. and on that side of the shaft or serialsupport major thms't or load resulting the pressure in the motorchambers. Becesses or on the opposite side of the axial supmay beconnected to low presume passageways or ports to prevent the aommmlemonof nressin'e which would counteract the By this system of balances theloads upon the hearings themselves is greatly-reduced.

The driving hell on the drive shah; extended Another feature of ourinvention is a displacement mechanism capable of running efficientlyateither low or high speeds,.acoording to the power and speed applied,without manufacturing different sizes, and adapted todo the'work ofwhich is mounted inside a hermetically sealed casing, the armaturepreferably being divided in two, one half on each port plate, to balanceelectrical end thrust. Each side wall or port plate is secured to theother through the shaft which is mounted on bearings outside of the portplates. The pinion or inner rotor is caused to revolve around inside theouter fluid displacement member or gear. In this way both an electricalbalance and a compression balance are provided. While this mechanism isdescribed-primarily 'as .a compressor it is obvious that it may bereversed withrespect to the ports and act as a motor; and when anelectric device is incorporated it becomes a generator.

The types of rotors or gears described and a claimed in the patent toMyron F. Hill, No. 2,03 l,-'

888, or No. 2,991,317 may be used in our invention.

In the drawings: Fig. I indicates a displacement mechanism with a motorbelt drive, and mounted on a horizontally disposed reservoir.

Fig. II is a longitudinal section of such a compressor on line II-H Fig.I.

Fig. III is a section, on line III-III of Fig. II showing an endbracketwith fluid passageways, reduced in size.

Fig. IV is an inside view of one of the port plates on line IVIV, Fig.11.

Figs. XXI, mm, XXHI show other bearing details, of the form of Fig. XV.

Fig. XXIV shows a motor (with the compressor inside) mounted on an airstorage tank.

Fig. XXV shows a section on line XXV of Fig. XXIV.

Fig. I shows a compressor in a shell l, driven by a belt 2, and a pulley3 on the shaft of a. motor 4. The compressor and motor may be mounted ona storage'tank 5. Figure I shows a left hand view of the compressorshown in sectional elevation in Fig. II.

Fig. II, shows the compressor shell or casing I, driven bythe belt 2.Inside the shell (and driven by it) is secured the outer rotor 6, whichdrives the pinion rotor l. The rotors 8 and I run between fixed sidewallor port members 8 and 9. The compressor shell I is carried by bearingmembers l0 and II journalled at [2 and I3, which thus also carry theworking load of the outer rotor 6. The pinion rotor is journalled on aneccentric bushing M, which has suflicient axial length to providesuitable running clearances for the rotorsfi and I. The stationary portmembers 8 and 9, eccentric bushing l 4, end bracket lfi, and collar I 9are fixedly mounted on the shaft'l5 which may be a stationary bolt. Theleft end bracket l5 contains the low pressure passageway I1 and the highpressure passageway l8. At the the nut 22 on the shaft l5is tightenedsolidly it fastens all the stationaryparts l6, 9, l4, 8 and i9 Fig. V isa section on line VV, Fig. II, show- -ing an end view of the rotors orgears.

Fig. VI is a section on line VI-VI of Fig. II

showing passageway details of a port plate.

Fig. VII is a sectional elevation of another form of our compressorinside an electric motor, with the outer gear member stationary, withasplit armature and 'with the inner rotor revoivingon two centers aroundinside the outer rotor or gear member.

Fig. VIII, the right half shows the outer gear member of the form 01Fig. VII fixedly mounted in a stator. The left half of the figure showsthe half armature of the form of Fig. VII mounted on one of the portplates.

Figs. IX and X show port plate details or the formofFig.VII'

Figs. x1, x11, x111, XIIIA, and xirv show rigidly together'by thrustingthem towards the bolt head 23. Member 6 has a running fit between portmembers 8 and 9. Bearing members ill and H have enough looser side wallrunning its as to avoid contact with both members 8 and i9, and 9 and I6respectively.- This shaft may also have additional support at its otherend as indicated by the bracket 24. The stationary shaft l5 and themember l9 may be one piece if desired. e

In operation the shell! is turned by the belt 2, which causes the rotors6 and l to rotate.

. Air or gas is sucked in through the passageways passageway and bearingdetails of the form oi Fig. xv is a sectional elevationof Fig. xvr online XV-XV.

Fig. XVI is a side elevation of one form of our invention shown in Fig.XV with theright hand Fig. XIX is a detail of the pinion rotor bearingof the form of Fig. XV.

' Fig. XX shows am an ed view of the frinies" used in our bearings ofthe form or Fig. XV.

and the hous- IT, 25 and into the intake port 26 (Figs. II, HI, IV) andthe opening rotor chambers 27 and 28 (Fig. V). The gas is thencompressed as the chambers readh the positions 29 and 30f and finallyexpelled out thru the discharge port at 3|, high pressure passageways32, and Hi. This port has alength sufllcient at Ma to overlap a rotorchamber in which the pressure has been raised to the desired degree. Itshould be separated from the intake port 26, (Fig. V) by a travellingtooth contact between the rotors or gears across full mesh, and ends atabout a point the length of a chamber from where the contacts betweenthe teeth begin to open, allowance for rotational speed being desirable.

From i8, the compressed gas or air may o to a storage tank 5 (Fig. I)thru the pipe 33. The compressed gas may be drawn oil from the tank thrua pipe and valve 34.

A pool of liquid used for'cooling gas (air for example) duringcompression, for pressurebalancing and for lubricating bearings isprovided in the tank 8 (Fig. I). I V

' We prefer to circulate liquid through the running parts of ourcompressor by using the pressure of the compressedgas or air to send-theliquid first to the three pressure balancing zones 5 and bearings at l2,l3 and 35. For this purpose we put enough liquid in the tank I to alwaysmore than cover the lower end of the return pipe 38 (Fig. I), the upperend of which may be screwed or sweated into the shaft II at 31 (Fig.11). The air pressure above the suri'ace oi the lubricant in the tanksends the oil into the passageway 38 and into the bore of the shaft"; InFig. V the duct 40 connects bore II with the circumferential groove IIto lubricate the eccentric bearing at 35 for the inner gear I. Thisforced feed liquid is'also introduced into the flotation channelsbetween the riilles of the pinion bearing under the rotor chamberscompressing gas and resists the resulting thrust of the pinion againstthe shaft on the compression side. The angular length of the groove 4idetermines the flotation,

area of the zone to balance the radial thrust of the mean eflectivepressure in compression chambers I, II and 30a.

In order to prevent thispressure from creeping around the shaft so faras to offset this "hydrostatic balance, the intake port may be extendedinward as indicated at 42 in Figs. IV and V to uncover the ends of therecesses between the rifles on the inner bore of th pinion rotor andassisted by the angular groove Ma, release any pressure in them. Theserecesses and zones are discussed more at length below;

Figures IV and VI show how the oil is conducted through the passagewayG3 to the grooves 44 (also Fig. 11) inthe port members 8 and 8.

Becaus compression in the closing chambers shaft, the load on bearingsi2 and I! has to be balanced by liquid pressure channels on the axialsupport on the sleeves or hubs of the side walls diametrically oppositethe discharge port and compression chambers. Holes l and 46 providing avent to the intake passage 26 at each end or the grooves ,serve toprevent the high pressure liquid from extending too far around the axialsupport and upsetting the hydrostatic balance.

The liquid acting now as a lubricant leaks from the recesses or channelsoi the high pressure zone toward the low pressure zones between theextent of cooling. The gas or air may be drawn oi! at 34 as abovementioned.

tends to thrust the outer rotor away from the A regulating valve for thelubricant may be inserted in the Pipe 36 at as (shown diagrammaticallyin Fig. I) and may be hand regulated or automatic as elsewheredescribed.

- Figure VII shows our compressor inside an'electric motor, havingcasing members and 58 with the outer gear 51 held stationary inside anelectric 7 shown the stator with 12 poles. The hermeti cally sealedhousing members ti and 62 prevent injury to the windings fromrefrigeration gases either during operation or when being repaired. Theouter edges of th members 6i and 82 are clamped in the casing joint bymeans of bolts to, and the inner edges may be welded at 51a to the outergear, 51. The armatures comprise copper frames", 64 with iaminations ofmagnetic iron Na and 64a in the holes "b and lb,

Fig. VIII. These poles vary in number as compared to the field poles inthe manner well known to the electrical motor art.

The armature is composed of a sufllcient amount of magnetic material tocooperate with the stator efliciently. In order to avoid electric endthrust we show the armature composed of two members 83 and SI, mountedon and keyed to port plates 85 and ii. These port plates are keyed tothe shaft II. On the shaft and keyed to it is an eccentric bushing 69 onwhich-the pinion gear 10 is free to rotate. This bushing 8! issufliciently thicker than the gears I1 and III to provide the slightclearances between them and the side port members '5 and CI tor-aneiiicient 45 free running compressor.

the rimning surfaces and into the intake port 28 p and the balancingdummy intake port 41 in the port member 8. Any liquid leaking outwardsfrom the pressure channels between the riilles of bearings l2 and I3 isdiverted by the smiling boxes or seals 48 and 49 into the cylindricalgrooves It and ii from whence it is sucked back through passageways 52and it to the intake passageways 2i and it (where inrushing air shredsit into a sort of rain) and ports 26 and 41 and into the opening rotorchambers where it new acts as a coolant to suppress the rise oftemperature which would result from adiabatic compression.

It willthus be seen, that a mixture of coolant liquid lubricant andcompressed gas passes through the rotors and is discharged'out at thedischarge port II, through passageways 32, II, and pipe 33 and into thetank 5, where the coolant flnds its way to the bottom to repeat itscircuit. Thus in this circuit the liquid has actedas a pressurebalancingagent in the pressure zones, as a lubricant for the bearing riflies andareas around the pressure zones, and as a coolan on the clearance in thejournal bearings and the .leakage from them which, assisted. by thepres- When the nut II is tightened, the rotating parts 88, 88, and 69are thrust against the shoulder 12 and rigidly fixed in position.

The armatures '3 and it drive the port plates 5 II and 66, the shaft andthe eccentric bushing it which cause the pinion gear ill to be rolledaround inside of the outer gear 51. so that in veilect the outer gear 51causes the inner gear II to rotate-on its own center while beingcarriedaround the shaft center by the eccentric II thus providingrelative rotation between the rotors.

The left half of Figure vm shows the misture it mounted on the portplate 58 and shaft This eccentric throw oi the pinion II createsVILVIILand x).

The axial supporting shaft 81 has outboard end bushings it and II whichmay have end closur and bearing members 18 and 19. The shaft has threeinterior passageways II, II, and 82. Passageways ii and 82 are connectedto- Bother as shown in dotted line in Figure VII.

sure created in the rotor chambers, determines 76 In operation, gas issucked in through the passageway. II in the casing member 55, thecylindrical groove ll, the intake port I! (Figs. VII, 1x and x) and intothe opening rotor chamports BI and 88 in port plates 63 and 65 cooperatein discharging gases from the compressor. Having been compressed thegases and entrained coolant liquid in them are'discharged through ports31 and 88, into passageways 09 and 90 and into the shaft passageway 30thenceout into the oil and gas separating chamber 9| issuing through thehole 92 which is of course rotating with the shaft at motor speed.Separation of the lubricant from the gas may be assisted by the cuppedbafiie plate 94 and disc 93. The passageways 30 and 8| may be plugged at86 and 91 as indicated in Fig. VII. The baflle plate 94 may have holesnear the shaft at 95 if desired. While we have shown only two suchbaille plates it is obvious that any number may be added so as to getemcient centrifugal liquid from gas separation. The

. clean gas then emerges from the compressor casing at 98 ready foruseeither to blow up tires, or for a refrigeration cycle.

After separation the pressure in chamber 9| forces the liquid throughthe passageway 99 and into the cylindrical groove I (Figs, 'VII and XIV)around the shaft, through the hole IOI' and V v into the shaftpassageways 8| and 82. The bushings I5, 11, and the recesses in theeccentric bushing 69 receive pressure balancing liquid from thepassageways 8| and 82 by way of ducts I02, I03 and I04 respectively,(Figs. VII, XI, and XIII). grooves I02a I03a and I04a (Fig. XI) feedingchannels I02b, M31) and "Me between the riilles of the various bushings.Each end of the shaft is subjected to the same discharge pressure sothat there is no unbalanced axial thrust and the whole compressor isthus in substantial hydrostatic, mechanical and electrical balance.

The intake ports may have undercuts at I 05 Fig. 1X to uncover the endsof the channels I04c in the eccentric bushing bearings to prevent theforce feed liquid pressure from creeping too far around the centralshaft.

The outer bearings may be relieved from a similar unbalance of pressureby such grooves as I06 Fig. XEV and I01 Fig. VII which allow the liquidto escape from the channels into the low pressure areas around the nutII and the shoulder I2.

As the liquid seeps from the channels and from the spaces between therotors or gears and their port plates it is flung out into the casingfrom whence it drains by gravity into the casing de-. pressions I08 andI09, through the passageways H0 and III and 2' into the intake passage93 fromwhence it may be sucked back into the compressor with theincoming gases. V

If the chamber 9I is unable to store enough liquid for operation, it maybe tapped off as indicated in dotted. lines at II 3 into some storagechamber (not shown) and then returned at full pressure and sprayed intothe intake at H4 (dotted lines) and also returned at full pressure tothe duct 99 for lubrication and flotation. Duct 99 in this instancewould have rro direct connection with duct I I3.

-In Figure XV is shown an outer housing I20 having ribs I2I within whichis mounted a stator of an electric motor, having for example laminationsI22, holding coils I23, I24 in circuits I23a escapee i p 'The coils I23may be for therunning current and I24 for the starting currenta Thesecoils may mounted upon a steel or iron ring I 26. The outer Ducts I02,I03 and I04 empty into the rel cage 'type of armature I25, such anarmature having greater inherent strength than a wired armature.

This armature or motor rotor I25, preferably of laminations inserted ina copper frame, may be rotor may be integral with the ring I26 or keyedto it at I21.

As the armature I25 rotates it carries with it the armature ring I26 andthe outer rotor I28.

This triple unit may be mounted upon side bearing members, I29 and I30which are provided with suitable radial eccentric flotation channels andbearings at I3I and I32. Those here em-- ployed will be described morein detail later. The members I29 and I30 may be of cast iron and arepreferably keyed to the armature ring I26 at I2'Ia and I211). The innerrotor I33 may be journalled upon a concentric bushing I34. The bearingsI3I and I32 in members I29 and I30 may be centered upon the axis I35 (FiXVI) of the outer rotorwhile the holes fitted to the fixed shaft or boltI36 are centered upon the axis I31 of the inner gear. The bushing I34may be of bronze or hardened steel, or of any,o ther suitable bearinmaterial to cooperate with the rotor I33 that turns upon it, it beingunderstood that the rotor'l33 may be, and preferably is of hardenedsteel, its bore being provided with'channels I38 (see Fig.

" XVI) separated by rifiles engaging the bushin similar to those shownin Fig. XX, riding upon liquid films between the riflles and bushing,de-

' scribed more in detail later.

The bushing I34 is longer axially than the rotors I28 and I33 toprovidefilm spaces between the side walls and the rotors. Sometimes the bushingexceeds the rotors axially by from one ten thousandth to one and a halfthousandths of an inch according to conditions of use; and when the sideor port members I39 and I40 are bolted solidly against its ends, by thebolt I36. their inner walls leave the rotors free to rotate.

The port members I39 and I40 may be of any suitable material, preferablymagnetic, so long as their inner walls cooperate in running qualitieswith the two gears.

The bushing I34 and port members I39 and I40 are held in correctrelative location by the pins MI. The bushing is centered on the boltI36 which in turn is tightly fitted to the side port members I39 and I40and to the cover members I42, and I43. The bolt is keyed at I44 to thelatter to prevent its rotation.

By'this arrangement all lathe work is concentric except the bores of themembers I39 and I40 which alone have accurate eccentricity (with re-"spect to the bearings I3I, I32) equal to that of and I24a -(Flg. XVI)suitable for two or more Phases of an alternatlngcurrent, one orwhich ina small motor might be a spli Ph the rotors.

The outer edges of the covers I42, I 43 may be bolted, riveted or weldedto the casing I20 in any .well known manner, in accordance with usualThe'armature I25, Fig.'XVI, shown in the drawings may have twenty-ninesquirrel cage inductive copper bars- I45 (Fig. XV) set up mechanical yand electrically in plural phase motors, perhaps of the split phasecapacitor supplied type, which have no switch members within the motor.While this may be one form, it is well within the spirit of starting andrunning, the other for running mainly, all wired as indicated in brokenlines. The coils I28 may carry the split phase and the coils I23 maycarry the main current from one wire of a three wire system. Thisarrangement provides 1880 R. P. M. Any other speed may be providedincludinga return wire. Three wires for this equipment from thecapacitor enter the casing through gas and pressure tight insulatedentrances, indicated at I48. These wires are connected to the coils inthe usual manner for such motors.

As the armature I25 drives the outer rotor or centers of the arcs of theteeth and of the toolgear, that gear drives the inner rotor or gear I33which rotates upon its journal on the bushin I34 opening and closingtooth spaces between the teeth. Since the outer gear drives the innergear the teeth makethe fluid tight engagement where the chambers areclosing,- an arrangement providing also a longer suction entrance I49(Fig. XVII) to the chambers that are opening than when the inner rotordrives the outer rotor.

Our continuous contact contours for holdin graduated pressure insuccessive chambers between the suction port I49 and the discharge portI50 provide high pressure ranges. g

The discharge port may begin at I5I (Fig. XVIII) for low gas pressureand at any point, such as I52 for higher gas pressure. I52 should belocated to connect with closing rotor chambers at the point where thedesired discharged pressure is attained in these chambers.

The port ends at full mesh are separated preferably bya toothdrivingengagement at a little less than the angular length of a tooth and toothspace. The arrow I58 in Fig. XVI indicates this distance and locationwhen the above mentioned rotors are employed, the engagement occurringpartly upon the opening side of a line through the axes I55 and I31 ofthe rotors (Fig. XVI) With such rotors, the teeth maintain tightengagement regardless 'of wear from the end I54 of a crescent area tothe end of the driving range near the point I55.

The suction port may extend from the point I55 to I54 though to shortenit at either or both ends does little it any harm to its cooperationwith the rotor chambers.

The open space between the teeth at open mesh extends from about I58 to.I54, these points being determined as a rule by the intersections of twocircles, one touching the inner tips of the outer rotor teeth and theother touching the outer tips of the inner rotor teeth.

Our rotors or gears are designed as follows:

Suitable circular arcs for the convex outer tooth faces are firstdecided on, and an inner mating tooth generated by it usinga Fellows earshaper if desired for generation purposes.

tioziih may be repeated to generate the other four During generation,both blank'and tool rotate upon the axes I35 and Ill, one completerotation of the tool generating one tooth space in the blank.

The outer rotor merely has repetitions of the selected arcs making upthe tooth form. The

have to be well outside of the outer pitch or ratio circle, at a.distance determined most easily by experiment. The proportions shown inFig. V21 are about right. It the centers or the arcs are too near theratio circle; the tool will undercut the portions of teeth engaging fromI58 to I55 ruining the rotors. A slight amount of back lash, perhaps acouplqthousandtbs of an inch, so that teeth ma not wedge at full mesh,in case of uneven expansion due to heat, is desirable. This may beaccomplished best by regenerating the inner rotor, after indexing it adegree or two.

The bottoms of the tooth spaces of the outer rotor gear should clear thetops of the Inner teeth in every position across two of an inch.

In M. F. Hill Patent No. 2,031,888 are shown and illustrated the latestform of rotors having a difference of one tooth. In those rotors a fullopen rotor chamber has a total depth of four ratio. Sincethey have 8 by10 teeth they have greater durability and driving efficiency than the v6 by 7 rotor and yet being based upon a 4 by 5 ratio in a given diameterhave a greater depth of chambers due to the greater eccentricity.

A fair comparison of these new rotors would be with a by 9 rotorsinvolving the principle set forth in Patent 2,031,888. Those 8 by 9rotors would have an eccentricity of slightly over half that ofcorresponding 4 by 5 rotors and when the relation of the total rotordiameter is taken into account the volumetric capacity of these 8 iacenttooth of the outer rotor. I In fact five alternate .outer rotor teethengage four alternate pinion teeth and the other four of the pinion areengaged by the remaining flve teeth on the outer rotor. In other wordsthis maybe a duplex system of rotors approximately doubling the capacityof an 8 to 9 pump with equal driving efllciency.

' The driving relation is much the same as in two The backing oil gearof the Fellows machine is one tooth division-45 for 8 teeth-theoperasets of 4 to 5 rotors with staggered teeth. Such a staggered systemmight be used with a partition between the rotors, and ports in thepartition to both rotors, and port plates on the outer sides of therotors.

These improvements depend upon a diflerence of two teeth asdistinguished from a diflerence of one. 7

If a difference oi three is desired the relative capacity is less andthe ratios are multiples of full mesh a thousandth or s'ordrmnyithnipesreplaclng way "I menflmedfabove. IDuetothehighpressureexistingaboveth'sur-I face oftheliquidbath fllandthe lowpressure rotor which has been cut into, to provide a toothspace; and the correspondin P rtion of the pinion' tooth spaces isoccupied with the inserted tooth. The lost radial displacement depth ofthe portions of the tooth and tooth space which have been so altered isbut a slight fraction of their original total depth and heightrespectively because of the original flatness of the curves wherealtered. The widths of the teeth are preferably age of high pressure gasacross the ends of the teeth is checked. These slots I59 tend to leavefilms upon the side walls of port members I39 and m which act as filmsfor the outer rotor teeth preventing leakage of gas over their ends.

This film seeps over the ends of the outer rotor and into the spacearound the members I29 and I3! and inside the armature ring I26 from Iwhence it assists in lubricating the journals m and I 32 in the lowpressure areas and then draining into the low pressure region within theeasing members I42 and I 43. The liquid drains downward to the bottomregions I80 and I6I in j Figure XV which are interconnected vby thegroove I82. a

In functioning, the gas .to be compressed enters the casing at I83 andis sucked through the motor parts, cooling them, and is then sucked intothe bottom passageway at I and up through tor. Liquid then enters thehole I15 in the bolt I36 and by means or the holes I18 and I11lubricates the bearingsand fills the flotation recesses in the highpressure regions at HI and I82 of parts I28 and I38 respectively. Theholes I18 and I11 are diametrically opposite the discharge port I 58.Thus liquid pressure to provide a counterthrust to the radial pressureon the inside of the outer rotor compressing chambers, gand thebalancing areas in these channels may be so proportioned by means ofgrooves I18 and I18 as to oppose or balance the radial thrust in theouter rotor. Two similar holes I88 and I8I force liquid into the abovementioned grooves I82, I83 and slots I59 of the pinion and also intothat part 01 the pinion bearing under the compressing chambers of thepinion so that it too has a balanced radial thrust. For this purpose thegrooves I82 and I88 (Figures XVI; and XVIII) are widened at I and I85respectively so as to introduce the pressure into the channels betweenthe rimes in this region. On the low pressure side of the pinion bearingthe channels are connected to the intake passageway I64, by passageway885a, Fig. XVIII, so that this pressure cannot creep around the shaft toupset this balancing function. Similarly channels in bearings HI and I32on the sideopposite to that sustaining the major radial thrust maybeopen at their-outer ends to the a i g I InFig. XX is shown an enlargedview of the the casing I43 and into the intake port at I49.

Any liquid that may have gathered at I80 or "I is sucked withrthe gas upinto the intake port I48 thus preventing the liquid level from risinghigher than the opening at I and so obstructing the rotation of the orsoaking the stator coils.

The compressed gas and excess liquid is discharged through the dischargeport I50 (Fig.

mi into the passageway I85, through the check valve I86, and, at I61into the high pressure cham;

ber I68. As indicated at I61 this high pressin'e gas enters thischamberI88 tangentially being choked so as to setup a swirling action. Thisswirling causes the liquid to be thrown out against the walls I" whereit drains into the bath "I;

preferably in a cylinder standing on end, actingv side walls. ,Thecomprmsed gas may be-drawn oil at "I above the liquid level and thenpass through my usual refrigeration cycle or cooling coils and expansionchamber before returning to the intake at I. The ball check I" preventscompressed fluids from blowing back' into the intake I48, through therotors or causing themto' withinthe compressorcasingthlslicuidisiorcedupward for bearing lubrication and hydrostatic i l cingastollowsz'yIfltheliquid Eaving entered isiorceduptopreieri ve m electromag- V ihaving metallic contact with its hearing. A pluas a pressure storagecontainer. If'cooling is de the liquid is cooled as it drains down theform of channels and riflies I prefer. The hearing shaft is'indicated atI86. The riflles I81 are between the recesses or channels I88. Therilfles have two surfaces, I89 which may be tangential to the curve ofthe bearing shaft I86 and the arc portion I90 which has a circularcurvature cooperating with the shaft surface I86. The bearing efiect issimilar to that of the Kingsbury thrust. If the riflle member travels inthe direction of the arrow then the liquid supplied for compressionfirst enters the space between the tangential portion'of the riille andis then swept onto the are so that the rotating member tends to ridecontinuously upon a film of liquid without 'rality of riilles provide asmany bearing areas.

The'friction load on the bearing under a given set of conditions isdetermined largely by the number and width of the recesses. The fitbetween them and the shaft should be responsive to the exigencies of thehearing. The material of whichthis bearing is made is anon-friablematerial and preferably tough and hard to resist damage when particlesof foreign grit enter. -In

- order to prevent excessive now the parts I28 and I30 may have bearingshoulders or hubs IQI and I82 respectively which substantially reducesuch flow into the low pressure regions to that required for thefunctions of bearing, balancing and as o l ns enum t *In Fig. is shownan air compressor system ior' compressing air and cooling the liquidwhich absorbs the heat of compression in the rotor cylindrical tank orstorage reservoir 283; The

\compressor discharges air mixed with a mist, my r 7 troduced at theintake, through the pipe in into netically controlled anddiagrammatically 'illustratcd by solenoid I 14 which is in circuit withthe motor and said valve is closed normally andmomentcui-rentpassesintothcmoat ZOI-(FIg. XXV) choked so that the airandmist are caused to whirl around insidethetanhthrowingthemlstoutwardlybyccntrii- .ugal force against'the innerwall of the tank.. downwhichitdrainsintothepoolatthebottom.

chambers. The motor 2", operating a comprese The wall absorbs the heatfrom the liquid and delivers it to the surrounding air. The liquid inthe bottom of the tank,.under pressure of the compressed air, is forcedthrough the strainer 206 and up through the pipe 201 to the compressor,where it enters the rotor chambers in a comminuted form as mist andrepeats its cooling function, and enters the channels inthe bearings asdescribed. An exit 209, having a valve at 208, provides for the use ofthe compressed air.

In Figs. XXI, XXII, and XXIII I show another form of my bearing.

In Fig. XXI is a shaft 2), a casing 2H,.a

rifled combined pressure balancing and bearing.

bushing 2l3, having bearing rifles and pressure zones of channels withconfining end ring members 2|2 and 2| 4, undercut at M6 and Mrespectively. (Figs. XXII, XXIII.)

Pressure forces oil or other liquid into the passageway 2H, and undercutgroove 2l6 (Figs. XXIII and XXI) extending across the ends of a seriesof rifles and into the channels (see I88 Fig, XX) between them. Therotation of the shaft then sweeps theliquid from the channels onto thebearing rifles or landings (see I86 Fig. XX) thus causing the shaft 2l0to ride on a series of liquid surfaces on the riflesunder hydrostaticpressure. The length of the are shaped groove 2l6 determines the highpressure area, which is designed sufiiciently large to meet loadrequirements.

In order to prevent hydraulic bearing area pressure from creeping so fararound theshaft as to offset the load balancing pressures from thegroove 2l6, another groove or undercut 2l5 with an escape passage ii tolow pressure is provided. The groove 2l5 extends over the end of asuflicient number of channels to satisfactorily unload the zone whereneeded;

While not absolutely necessary, I prefer that 40 the lubricant'be forcedin at oneend of the zone,

being connected by a duct to said high pressure port, and low pressureregions between said support and rotors, and opposite to said highpressure areas, having a duct connection to a low 5 pressure region;whereby varying fluid pressures in said rotor chambers create opposingforces to corresponding mechanical pressures upon said bearings.

2. The combination claimed in claim 1, in

10 which the low pressure duct connection acts-as an escape connectionfor liquid leaking from the high pressure areas to the low pressureregion, said escape connection leading to the low pressure port, wherebyshaft seals or packing are rendered unnecessary.

open and close during relative rotation of said fluid pressures in saidchambers during opening rotors, members providing ports to receive gasfrom and discharge gas into said chambers, said ports being soproportioned and located with respect to said chambers as to providevarying or closing thereof, said teeth havin contours maintainingcontinuous contacts between said chambers, said chambers during openingor closing containing said varying fluid pressures and being kept insealed relation by the driving contacts between said teeth to check airor gas leakage under pressure from one to another while performingpressurefunctions, a support for said rotors providing said eccentricmounting, said support including relatively fixed pressure conthenceinto the high pressure channels, thence over rifles and to the lowpressure channels, and

then allowed to escape at the other end inside of the ring. The exit M8is so located above the shaft that when the shaft is stationary, thereis n0 tendency for lubricant to drain through it away from the zone.Close running bearing clearances at the ends of the channels, preventthe zone from becoming completely. dry during periods of idleness.

What we claim is:

1. In a mechanism for operation on or by fluids, rotors or gears mountedeccentrically to each other, one within the other, said rotors havingteeth forming chambers between them which, open and close duringrelative rotation, said teeth havin contours maintaining continuouscontacts between said chambers while performing fluid pressurefunctions, a support forsaid rotors providing said eccentric mounting,said support including pressure confining side walls closing saidchambers at their ends, high and low pressure ports connectedalternately to said chambers for supplying and receiving fluid for saidoperation,- bearings for said eccentrically mounted rotors disposedalong said support to prevent said rotors from tilting at angles to eachother, high pressure fluid areas between said support and rotors saidareas located between said support and rotors, on both sides of a middleplane thru said rotors normal to their axis, and

filling side walls closing said chambers at their ends, said side wallshaving a fixed relation to said support, and means to supply mist tosaid a coolant to check change of temperature during variations of gaspressure in-said chambers, said chambers, tooth contacts and ports beingsov located and adjusted as to prevent liquid locking or choking betweenhigh and low pressure ports at full mesh.

. separated by centrifugal force.

5. The combination claimed in claim 3, said rotors having a differenceof two in the numbers of their teeth thereby leaving a'crescent spacebetween the teeth at open mesh, said low pressure port connected to saidcrescent space to increase the ease of passage of low pressure gasesthru the low pressure port.

6. In a mechanism for operation on or by gas and liquid, rotors or gearsmounted eccentrically to each other, one within the other, said rotorshaving teeth forming chambers between them which open and close varyinggas pressure between them, said teeth having contours maintainingcontinuous contacts between said chambers during opening or closing ofsaid chambers to check air or gas leakage from a chamber containinghigher pressure to a chamber containing lower pressure while performingpressure functions, said teeth having a difference in their soproportioned as to substantially balance the radial mechanical pressuresof said rotors upon said eccentric bearings, said high pressure areas 76of, high and lowpressure gas ports and passagenumbers .of teeth greaterthan one, a support for said rotors providing said eccentric mounting,said support carrying side walls for saidrotors closing their chambersat the ends therero'tor'chambers as their pressures vary, to act as waysconnected alternately to said chambers and disposed angularly about saidsupport so as to be separated by chambers varying in their pressure,bearing members for each of said rotors between said rotors and saidsupport disposed axially of said rotors to maintain line contactsbetween said teeth from one side wall of said rotors to the other sidewall or said rotors.

7. The combination in claim 6 havingmeans to supply mist to saidchambers to check variations of temperature as their volumes andpressures vary.

8. The combination claimed in claim 6 having pressure areas between saidrotors and said support supplied with fluid or liquid pressure from saidhigh pressure port, said areas located to relieve the radial mechanicalpressure upon said hers. I

port and between it and said rotary members 10- 'cated to oppose theradial mechanical pressure resulting from varyin as pressures in saidchambers upon said rotors, ducts connecting said high pressure zones tosaid high pressure port, and said low pressure zones to a low pressurere-' gion, whereby the load on said bearings is reduced increasing thetotal load capacity of said rotors for compression.

MYRON F. m. Farmers A. HILL, 22m.

